function test(){
    let age
    
    function setage(v) {
        if(typeof v === 'number'){
            if(v > 0 && v <= 100){
                age = v
            }else{
                age = 20
            }
        }else{
            age = 20
        }
    }

    function getage() {
        return age
    }

    return {
        setage,
        getage
    }
}

let obj = test()
obj.setage(400)
console.log(obj.getage())